In a typical land mobile radio system, such as a mobile cellular telephone system or personal communications network (PCN), a plurality of cells are defined which make up the system. Each cell is a geographically defined area wherein communications are handled by a land mobile radio base site (cell site) for mobile units operating within the boundaries of the cell. Although these cells are often represented as hexagons in cell design schemes, in reality, due to terrain and the presence of buildings and other structures, the actual boundary of a cell may have an irregular shape.
As is well known in the art, cell layouts are typically characterized by a frequency reuse pattern where a number of different frequency sets are defined. Each cell uses a particular frequency set, and the cell layout is designed to provide the maximum separation between cells using the same frequency set so as to minimize interference.
It is generally required, depending on the location of the cell site within a cell, that the cell site antennas provide coverage for communications over 360.degree. of azimuth in order to effectively cover the corresponding geographic area. In most existing base sites, either omni-directional antennas or panel antennas are used to provide the 360.degree. of azimuth. If panel antennas are used, the 360.degree. of azimuth is divided into a number of smaller sectors, such as three sectors, with each sector provided with a pair of antennas each having a beamwidth of 120.degree.. A problem associated with such base sites is that even with frequency reuse patterns and strategic positioning of the base sites, unavoidable interference often occurs which degrades the quality of communications between mobile radio units and the base site.
Recently, base sites have been developed having a sectorized antenna configuration wherein a large number of directional antennas or antennas having a large number of directional beams are employed. It would be desirable to control such a base site to more accurately monitor and avoid potential interference to thereby maintain a high quality of communications between mobile radio units and the various base sites in a land mobile radio system.